1. Field of the Invention
The present invention relates to a semiconductor device. In particular, the present invention relates to a DCDC converter utilizing semiconductor characteristics.
2. Description of the Related Art
A DCDC converter including both a transistor containing silicon (Si) in a semiconductor layer to be a channel formation region and a transistor containing an oxide semiconductor (OS) in a semiconductor layer to be a channel formation region (the latter transistor is hereinafter referred to as “OS transistor”) is proposed (see Patent Documents 1 and 2).